Technology Field
The present invention relates to a data writing method for a rewritable non-volatile memory module, a memory control circuit unit and a memory storage apparatus using the method.
Description of Related Art
Along with the widespread of digital cameras, cell phones, and MP3 in recently years, the consumers' demand for storage media has increased drastically. Since a rewritable non-volatile memory has several characteristics such as non-volatility of data, low power consumption, small size, non-mechanical structure, and fast reading and writing speed, the rewritable non-volatile memory is the most suitable memory applied in a portable electronic product, e.g., a laptop. A solid state drive is a memory storage apparatus adopting a flash memory as a storage medium. Therefore, the flash memory industry has become a very popular part of the electronic industry in recent years.
When the data is written into the rewritable non-volatile memory, a program fail may be occurred in the rewritable non-volatile memory, and the data writing is unsuccessful. Hence, at least one buffer memory would be disposed within a memory storage apparatus in general. The buffer memory is adopted for temporarily storing the data desired to be written to the memory storage apparatus. In other words, data to be written to the memory storage apparatus is stored in the buffer memory first, and then the data is written to the rewritable non-volatile memory from the buffer memory. Therefore, for writing data, the writing and reading operations on the buffer memory are both needed. As a result, when the transmission bandwidth of the buffer memory is not large enough, the bandwidth allocated for the data writing is relatively less.
Moreover, when the data is temporarily stored in the buffer memory, a control circuit of the memory storage apparatus sends a signal, which indicates that the command is accomplished, to a host in order to receive the next command and data. When the data is written to the rewritable non-volatile memory, a program fail may be occurred, and the data writing is unsuccessful. Accordingly, the control circuit of the memory storage apparatus has to write the data stored in the buffer memory into the rewritable non-volatile memory again (This is also called “a rewrite operation”) where the data writing was failed. As a result, the buffer memory disposed in the memory storage apparatus has to be large enough in capacity to temporarily store the data so as to perform the rewrite operation.
In light of the foregoing descriptions, in order to increase the writing speed, a buffer memory with large bandwidth is required. However, for the requirement of rewriting, a large storage capacity buffer memory is also needed. Regarded to a buffer memory with large bandwidth, the cost of each memory unit is relatively high. Therefore, how to lower the production cost but still keep a buffer memory with appropriate capacity and bandwidth is the most concerned topic for the persons skilled in this art.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.